Light fixture



I May 18 1926.

A. F. DlCKERSON LIGHT FIXTURE Filed Oct. 5 1923 lllllllllllllllllllHllHlHll IIIIIIIIIIIIIIIIIIIHI ii [if In vehtor: Adolph F. DicK er's on,

1%; His Attorney. 4

Patented May 18, 1926 UhllTE STA'llEd PATENT OFFICE.

ADOLPH F. DICKERSOIN, F SCI-IE N ECTADY, NEV] YORK, ASSIGNQR IO GENERAL ELEC- ERIC COMPANY, A OGRPOli-ATION OF NEXV YORK.

LIGHT FIXTURE.

Application filed October 3, 1923. Serial No. 666,415.

lily invention relates to a novel lighting fixture. 'lhis lixture comprises a globe of a novel construction which is especially adapted for use in combination with an electric lamp and especially one of high candle power. The fixture of my invention is of such construction that it etliciently utilizes the light from the light source and it particularly lends itself to the regulation and distribution of light both in the foreground and in the background, thereby ensuring a lighting unit free from any objectionable glare. Furthermore, the design of the globe which surrounds the light source is such that the amount of illumination in the background may be varied by merely varying the area of the metallic reflecting surface which used in connection with the globe. Furthermore, the fixture is of such design that the losses from the emission of horizontal rays delivered directly from the light source are avoided since the rays that would ordinarily be lost in a horizontal direction are properly directed so as to become effective in illun'iinating the particular and restricted area intended. Furthermore, the fixture is so designed as to ensure a lateral spread of light and the degree of intensity desired with great efficiency.

The novel fixture of this invention is characterized by other details of improvement tending to increase the efficiency and serviceability of a device of this character.

The means for accomplishing the foregoing and other useful ends are hereinafter more fully set forth and claimed.

Referring to the accompanying drawing which is made a part of the specification, the figure is a view partly in cross section and partly in elevation showing the globe inclosing the source of light both of which are secured to a supporting base.

Referrin more in detail to the drawing, it will be observed that the holder 2 stands over the fixtme, which holder may be attached to a ceiling, for example. As shown, the globe is made in the form of a unit with a single opening 4; above, below which opening there is provided a neck which is engaged by suitable screws such as the screw 5 for holding the globe in place. Below the neck, the globe flares out in the form of a surface of revolution 6, such for example as a paraboloidal surface of revolution.

This paraboloidal surface 7. This conic portion of the globe is closed by the curved surface 8. As indicated in the drawing, this surface which forms the base of the conic section, extends toward the center, first horizontally, and then gradually slopes downward and develops into a concave area on the inside. The particular form of this base of the conic section of the globe may be varied to suit the character of illumination desired immediately below the fixture. Instead of curving downward, the base of the globe may be curved upward as indicated by the dotted line 9. On the outside of the globe, 1 provide a metallic reflecting medium such as, the silver surface 10. This metallic reflecting surface overlaps both the conic section and the paraboloidal section, but overlaps only a portion of the latter, an opening be ing thus provided between the metallic surface and the neck of the globe through which rays of light from the light source may pass to the background, thus illuminating the background and avoiding any objectionable glare. It will be understood that the extent of the paraboloidal area covered by the metallic reflecting surface may be varied, that is, the area between the reflecting surface and the neck may be reduced by extending the metallic surface toward the neck, or it may be increased by terminating the metallic surface nearer the outward edge of the paraboloidal section. It will be seen that with a globe of this construction, some of the rays of light from the pass upwardly through the surface 6 for illuminating the background. Some of the rays will strike that portion of the silver which overlaps the paraboloidal section and will. be reflected downward in a direction generally parallel with the major axis of the paraboloidal surface and of the unit. Still other rays from the light source will strike the reflecting silver surface. These reflected rays are spread so as to spread over the base 8 of the globe. This base 8 may be either of clear glass or it may be of a diffusing type, opal color, for example. With the dif fusing base, the illumination downward will be of course spread and the intensity of illumination immediately below the unit will be reduced. Furthermore, with the downward curvature of the base 8, as shown in the area merges into a conic i light source drawing, the lateral spread of the lighting beam will be greater than if the base is horizontal, or if it is curved as indicated.

In the same manner that the spread of the light may be varied below by varying the character of the glass from which the globe is made, the spread of the light at the background may be varied by making the unsilvered area below the neck of the globe either clear glass or of a diffusing glass, such as opal colored glass.

It will be understood that I do not wish to be restricted to the forms of my invention specifically described and illustrated inasmuch as variations of my invention will readily suggest themselves, as a result of my disclosure,,to others who are specialists in this art.

Vhat I claim as new and desire to secure by Letters Patent of the United States, is:

1. In a lighting fixture, a unit globe and a source of light, the globe having a paraboloidal zone and a conoidal zone, both zones having a common major axis, the focal plane of the paraboloidal zone cutting the conoidal zone in combination with a metallic refleeting surface on the globe, said surface covering a portion of the conic section and only a portion of the paraboloidal section.

2. A flaring glass globe adapted to be mounted in an inverted position having the upper section in the form of a conicoidal surface of revolution and the sides in the form of a cone, the upper section and the sides both sloping in the same direction, the base of said cone being closed over by a translu cent surface and a reflecting surface overlapping both said upper and side sections, said globe having a zone above and a zone below the reflecting surface through which light may be transmitted, the globe and the reflecting surface being so formed that both reflected and direct light are transmitted through one clear zone and only direct light through the other clear zone.

In Witness whereof, I have hereunto set my hand this 2nd day of October, 1928.

ADOLPI-I F. DICKERSON. 

